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/*BEGIN_COPYRIGHT_BLOCK
*
* Copyright (c) 2001-2008, JavaPLT group at Rice University (drjava@rice.edu)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the names of DrJava, the JavaPLT group, Rice University, nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* This software is Open Source Initiative approved Open Source Software.
* Open Source Initative Approved is a trademark of the Open Source Initiative.
*
* This file is part of DrJava. Download the current version of this project
* from http://www.drjava.org/ or http://sourceforge.net/projects/drjava/
*
* END_COPYRIGHT_BLOCK*/
import java.io.*;
import java.util.Date;
import java.text.SimpleDateFormat;
import java.util.TimeZone;
/** Logging class to record errors or unexpected behavior to a file. The file is created in the current directory,
* and is only used if the log is enabled. All logs can be enabled at once with the ENABLE_ALL field.
* @version $Id: Log.java 4691 2008-12-02 23:33:27Z dlsmith $
*/
public class Log {
public static final boolean ENABLE_ALL = false;
/** Whether this particular log is enabled in development mode. */
protected volatile boolean _isEnabled;
/** The filename of this log. */
protected volatile String _name;
/** The file object for this log. */
protected volatile File _file;
/** PrintWriter to print messages to a file. */
protected volatile PrintWriter _writer;
public static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("d MMM yyyy H:mm:ss z");
static {
DATE_FORMAT.setTimeZone(TimeZone.getTimeZone("GMT"));
DATE_FORMAT.setLenient(false);
}
/** Creates a new Log with the given name. If enabled is true, a file is created in the current directory with the
* given name.
* @param name File name for the log
* @param isEnabled Whether to actively use this log
*/
public Log(String name, boolean isEnabled) { this(new File(name), isEnabled); }
public Log(File f, boolean isEnabled) {
_file = f;
_name = f.getName();
_isEnabled = isEnabled;
_init();
}
/** Creates the log file, if enabled. */
protected void _init() {
if (_writer == null) {
if (_isEnabled || ENABLE_ALL) {
try {
FileWriter w = new FileWriter(_file.getAbsolutePath(), true);
_writer = new PrintWriter(w);
log("Log '" + _name + "' opened: " + DATE_FORMAT.format(new Date()));
}
catch (IOException ioe) {
throw new RuntimeException("Could not create log: " + ioe);
}
}
}
}
/** Sets whether this log is enabled. Only has an effect if the code is in development mode.
* @param isEnabled Whether to print messages to the log file
*/
public void setEnabled(boolean isEnabled) { _isEnabled = isEnabled; }
/** Returns whether this log is currently enabled. */
public boolean isEnabled() { return (_isEnabled || ENABLE_ALL); }
/** Prints a message to the log, if enabled.
* @param message Message to print.
*/
public synchronized void log(String message) {
if (isEnabled()) {
if (_writer == null) {
_init();
}
_writer.println(DATE_FORMAT.format(new Date()) + ": " + message);
_writer.flush();
}
}
/** Converts a stack trace (StackTraceElement[]) to string form */
public static String traceToString(StackTraceElement[] trace) {
final StringBuilder traceImage = new StringBuilder();
for (StackTraceElement e: trace) traceImage.append("\n\tat " + e.toString());
return traceImage.toString();
}
/** Prints a message and exception stack trace to the log, if enabled.
* @param s Message to print
* @param trace Stack track to log
*/
public synchronized void log(String s, StackTraceElement[] trace) {
if (isEnabled()) log(s + traceToString(trace));
}
/** Prints a message and exception stack trace to the log, if enabled.
* @param s Message to print
* @param t Throwable to log
*/
public synchronized void log(String s, Throwable t) {
if (isEnabled()) {
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
t.printStackTrace(pw);
log(s + "\n" + sw.toString());
}
}
/** Closes a log file. */
public void close() {
_writer.close();
_writer = null;
}
}
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